Photographic product and process



y 1, 1966 A. J. SABLE 3,253,916

PHOTOGRAPHIC PRODUCT AND PROCESS Filed Sept. 12, 1962 FIG. 3

1N VEN TOR.

MyM BYWAZQW AT ORNEYS United States Patent This invention relates tophotographic products and processes and more particularly to processesfor producing photographic prints and products useful therein.

Diffusion-transfer reversal processes in which a liquid processingcomposition is distributed between and in contact with an exposed layerof a photosensitive imagerecording material and another layer superposedtherewith and reacted with the image-recording material to produce apositive transfer print supported on the other layer are well known inthe art. In connection with such processes, it has been proposed toprovide the layer of image-recording material on one side of asupporting sheet and, following exposure, process the image-recordingmaterial by coiling the sheet upon itself while distributing the liquidprocessing composition between the image-recording layer and the otherside of the supporting sheet to form a transfer image thereon. In suchprocesses each sheet, when exposed and treated with a liquid, wouldconstitute a photographic print and, with the exception of the liquid,provide all of the materials required to produce a print.

It is contemplated that the sheet would be coiled and a liquidcomposition distributed between opposite sides of successiveconvolutions of the coiled sheet by advancing the sheet between a pairof juxtaposed pressure-applying members one of which functions as asupport around which the coil is formed. Each succeeding convolution ofthe coil is brought into superposition with the previous convolution atthe bite, i.e., between the jaxtaposed members, where a mass of theliquid is provided for distribution between adjacent surfaces of thesheet as successive portions of the sheet surfaces are brought intosuperposition at the bite of the members. After the liquid has beendistributed between and in contact with the areas of the sheet surfacesto be treated, an undistributed mass of the liquid still remains betweenthe sheets at the bite of the juxtaposed pressure-applying members. Theproblem is to collect, retain and dispose of this (now) excess liquid soas to prevent the liquid from being distributed beyond the trailing endof the sheet into contact with one of the pressure-applying members and/or the outer surfaces of the outer (last) convolution of the coiledsheet.

An object of the invention is to provide a novel and improvedphotographic product useful in a method of photography as described andincluding means for collecting and retaining, for disposal, processingliquid in excess of that utilized to treat the image-recording materialwhile facilitating disposal of this excess liquid.

Other objects of the invention are: to provide a novel and improvedphotographic process of the above type to produce a finishedphotographic print rapidly and easily and requiring a minimum of simple,inexpensive apparatus; and to provide a method as described in which theliquid employed is confined at all times by thesheet materials, andexcess processing liquid is readily and easily separated, for disposal,from the finished print.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the process iiivolving the severalsteps and the relation and order of.

ice

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawing wherein:

FIGURE 1 is a somewhat schematic, sectional view illustrating the methodof the invention and a photographic product useful therein;

FIG. 2 is a View similar to FIGURE 1 illustrating another step in theprocess; and

'FIG. 3 is a fragmentary view similar to FIG. 2 illustrating anotherstep in the method. of the invention.

The present invention is concerned with. the production of positivephotographic prints by a method which can be performed easily andrapidly with a minimum of simple, inexpensive apparatus and utilizesmaterials in themselves inexpensive. It is in the furtherance of thesaims that it has been proposed to produce the positive image comprisinga print by a diffusion-transfer reversal process on the opposite side ofthe sheet carrying the photosensitive image-recording material fromwhich the positive transfer image is formed. The invention finds specialutility and advantage in document copying where it is desirable toproduce a positive copy of a document inexpensively on a sheet of papersimilar in size and shape (usually rectangular) to the originaldocument; and wherein anegative image on the reverse side of the copyfrom the positive is not considered particularly objectionable although,if desired, provision can be made for stripping the negative image fromthe support which carries the positive print.

The single sheet supporting the image-recording material followingexposure of the latter is coiled upon itself with the image-recordingmaterial innermost so that the exposed area of the image-recordingmaterial is superposed with another area of the opposite surface of thesupport sheet. The support sheet is usually coiled around a cylindricalsupporting member while the liquid is distributed between and in contactwith the outer surface of one convolution and the inner surface(image-recording material) of the next convolution. The processingliquid is initially provided. on the sheet as .an elongated mass locatedadjacent the leading end of a surface of a portion of the sheet to betreated and is distributed between convolutions of the sheet by theprogressive application of compressive pressure to portions of the sheetsucceeding from its leading end. A compression. member is provided injuxtaposition with the cylindrical supporting member for superposingsuccessive convolutions of the sheet and distributing the processingliquid therebetween during movement of the sheet into the coil betweenthe supporting and compression members. The sheet is permitted to remainin a coiled condition for a predetermined period during which the liquidis reacted with the image-recording material to produce a positivediffusion-transfer reversal image on the side of the sheet opposite theimage-recording material. predetermined time, the sheet is uncoiledtoreveal-a positive image on one side and a negative image on the otherside, the latter of course being displaced toward the trailing end ofthe sheet from the positive image by a. distance at least equal to thelength of the first convolution. This portion of the sheet at thetrailing end supporting only a negative image on one side may, ifdesired, be trimmed from the remainder of the sheet supporting thepositive image and the major portion of the negative image.

Reference is now made to FIGURE 1 of the drawing wherein there isillustrated a photographic product constructed according to theinvention and useful in the method thereof together with the essentialcomponents of apparatus for performing this method. The productcomprises a first or support sheet 12 the thickness of which At the endof this:

is shown in the drawings as exaggerated for purposes of illustration, itbeing understood that in practice the thickness of the sheet may be onthe order of .001 to .004 inch. Supporting sheet 12 may be formed of anyof the usual film base materials used in photography; however, paper ispreferred because of its low cost and particularly when the purpose forwhichit is to be employed is the copying of documents. Sheet 12 isgenerally rectangular in shape and, with the exception of its lengthabout which more will be said later, may conform substantially to thestandard size or sizes of paper generally used commercially, e.g., 8 /2X 11 inches or 8% x 13 inches. Sheet 12'is coated on one surface with alayer of a photosensitive image-recording material such as a gelatinosilver halide emulsion. This layer is approximately equal in size to theprint which is to be made, i.e., the original document to be copied, andmay include a leading edge spaced from the leading edge 14 of sheet 12toward the trailing edge 16 of sheet 12. The layer of photosensitiveimage-recording material may, if desired, completely cover one side ofsheet 12; or, in another embodiment, the layer of photosensitivematerial may terminate, as suggested, a predetermine distance from theleading edge of the sheet.

The image-recording layer is photoexposed in a conventional manner toproduce an image therein. Exposure may be accomplished by animage-forming optical system or, in the case of document copying, eitherby direct or reflex exposure in conjunction with the document beingcopied. Following exposure, sheet 12 is attached at its leading end to acylindrical supporting member 18 which may be rotated in order to coilsheet 12 around the periphery of the supporting member. The diameter ofsupporting member 18 is preferably as small as possible consistent withmaintaining the requisite structural strength and rigidity inasmuch asthe length of each convolution of the sheet, and particularly the firstconvolution which is essentially waste, is a function of thecircumference of roll 18. Various mechanisms may be employed forsecuring the leading end of sheet 12 to roll 18, a preferred mechanismbeing to provide a pressure-sensitive adhesive on the leading endportion of sheet 12 on the same surface thereof as the layer ofimage-recording material. In an alternative embodiment, the leading endportion of the sheet and a section of the roll periphery may be providedwith a contact adhesive having substantial sheer strength, yetrelatively little strength in tension so that the sheet may be readilystripped from roll 18 when processing is complete.

Sheet 12, in the form shown in FIGURE 1, is coiled on roll 18 with theimage-recording materialcontaining. the negative image facing inwardly,this arrangement being preferred over an arrangement in which theimagerecording material faces outwardly because it locates the wastematerial at one end of the sheet. The processing liquid, which ispreferably quite viscous, is provided on sheet 12 on the same surfacethereof as the imagerecording material. The processing liquid ispreferably dispensed from a tubular container 20, very much like adrinking straw, as an elongated uniformly distributed mass extendingsubstantially from side to side of the sheet or at least the areathereof to be treated, and located toward the trailing end of the sheetfrom the leading end of the sheet by a distance approximating thecircumference of roll 18, i.e., the length of the first convolution ofthe sheet. The mass of liquid islocated on the sheet so as to becomedisposed between the outer surface of the coiled sheet at the leadingend portion thereof and the inner surface of the coiled sheet at theleading edge of the area in which the positive transfer image is formed.The leading edge of the negative image, it will be noted, is thus spacedfrom leading edge 14 of sheet 12 by a distance greater (by the width ofthe mass of liquid) than the circumference of roll 18, and acorresponding section at the opposite '(trailing) end of sheet 12 whichmay be considered to constitute waste material.

the supporting member is provided for distributing the processing liquidbetween and in contact with adjacent surfaces of superposed convolutionsof sheet 12. Although pressure member 22 is shown as a cylindrical roll,it may comprise any form of member providing a surface tangent with thesurface of roll 18 along an axial line on that surface. For example,pressure member 22 may comprise a flat plate or bar which is eithermovable toward and away from roll 18, and is biased toward the roll.Roll 18 and member 22 may comprise rigid materials such as metal orslightly pliant materials such as hard rubber and are designed to applycompressive pressure to the sheet progressively from its leading edgetoward its trailing edge as the sheet is being coiled upon roll 18.

As previously noted, the invention contemplates the formation of apositive diffusion-transfer image on the opposite surface of sheet 12from the exposed imagerecording material. Processes of this type andmaterials useful therein are disclosed in US. Patent No. 2,662,822,issued December 15, 1953, in the name of Edwin H. Land. Typicalmaterials include silver halide as the image-recording material whilethe liquid processing composition comprises a silver halide developer, asilver halide solvent and an agent providing a silver precipitatingenvironment for promoting the reduction of silver halide. Theimage-recording material may be coated on one side of ordinary bondpaper while the transfer image is produced on the opposite side of thepaper which requires substantially no special preparation for thispurpose. During the processing, exposed silver halide is devolped toproduce a negative image while a soluble silver complex is formed fromundeveloped silver halide and is diffused from the silver halide layerand reduced to form an image in silver which is the positive of thesubject matter of the latent image in the silver halide. The processingliquid may be distributed between opposite surfaces of sheet 12 as athin layer in which the positive transfer image is formed. This layer isthe result of the inclusion in the processing liquid of a thickening orfilm forming agent such as sodium carboxymethyl cellulose. However, in apreferred form of the invention, the processing liquid which isthickened to facilitate distribution is advanced between adjacentsurfaces of the sheet primarily to effect the Wetting of one or bothsurfaces of the sheet which absorb reagents from the mass of viscousliquid as the latter is moved relative to and in contact with the sheetsurfaces. It is noted that in this latter process, even though thepurpose of liquid distribution may not be to spread the liquid in alayer, the viscosity providing agent, being a film-forming material,tends to adhere to the sheets to form a layer which may be extremelythin; and this layer, however thin, is formed between the sheets andperforms the function of retaining the convolutions of the sheets insuperposition during the period required for formation of a transferimage. The silver transfer image is precipitated in the pres nce of theaforementioned precipitating agent, e.g., solid minute particles of asubstance insoluble in the liquid for accelerating the reduction by thedeveloper of silver bearing ions in solution; and this silverprecipitating agent becomes afiiliated with the surface of sheet 12resulting in the formation of the transfer image thereon.

Coiling of sheet 12 and distribution of the processing liquid, hereindesignated 24, is continued until the trailing edge of the exposed areaof the image-recording layer has been advanced into superposition withthe surface of the opposite side of sheet 12 to-form a coil such as isshown in FIGS. 2 and 3 in which the layer of photosensitiveimage-recording material and the layer of liquid, which may be extremelythin, are designated 26. The

mass of liquid at the bite of members 18 and 22 where successiveconvolutions of the sheets are brought into superposition may beconsiderable; and, in accordance with the invention, provision is madefor collecting and retaining this mass of liquid now considered excessso that continued advancement of the sheet between members 18 and 22does not result in distribution of the mass of liquid in contact withmember 22 and/or the outer surface of sheet 12 at the trailing endportion thereof. The means for collecting and retaining excessprocessing liquid comprises a trapping sheet 28 secured to the oppositeside of sheet 12 from the image-recording material at the trailing edgeof the area in which the transfer image is formed. Trapping sheet 28comprises a generally rectangular sheet of a material such as paperpreferably equal in width to the width of sheet 12 and having a lengthsubstantially less than the length of sheet 12 and just suflicient tocollect and retain the excess processing liquid.

Trapping sheet 28 is secured at its leading edge portion to sheet 12 bya strippable adhesive designated 30 so that at least the trailing edgeportion of trapping sheet 28 is free for movement with respect to sheet12. Roll 18 is rotated to cause the leading edge of trapping sheet 28 toenter the bite between members 18 and 22 on two successive occasions.During the first passage between members 18 and 22, trapping sheet 28 islocated outermost and performs no function. However, during the secondpassage of the trapping sheet between members 18 and 22, the trappingsheet is disposed between successive convolutions of sheet 12, and thepressure exerted by member 22 is relieved so as to provide a spacebetween trapping sheet 28 and the trailing end portion, designated 32,of sheet 12 in which the mass of excess processing liquid is collectedand retained. The effect trap-ping of the excess processing liquid,member 22 is preferably displaced away from member 18 to provide theabovedescribed space between trapping sheet 28 and trailing end portion32 of sheet 12. Trailing end portion 32 is preferably coextensive withtrapping sheet 28 and includes a leading edge spaced along sheet 12 fromthe leading edge of trapping sheet 28 by the length of the convolutionof sheet 12 including the trapping sheet and the trailing end portion ofthe negative image, preferably so that trailing edge 16 of sheet 12andthe trailing edge of trapping sheet 28 are aligned when sheet 12 iscompletely coiled upon itself around roll 18.

The invention provides for separating the portion of the productretaining the collected excess processing liquid from the portion ofsheet 12 comprising the positive print. To facilitate this separation,sheet 12 is precut, perforated or otherwise weakened at the leading edgeof trailing end portion 32 along a transverse line designated 34. Sheet12 is allowed to remain in a coiled condition during a predeterminedimbibition period at the end of which the trailing end portion 32 andtrapping sheet 28 are withdrawn from the coil, which is facilitated bythe fact that there is no processing liquid between trapping sheet 28and the outer surface of the preceding convolution of sheet 12. This maybe accomplished by manually grasping the trailing end portion and thetrapping sheet between the fingers, since the latter do not come intocontact with the processing liquid, as the liquid is retained betweenthe trapping sheet and the trailing end portion. Simultaneously with thewithdrawal of the trailing end portion of the trapping sheet from thecoil, the trailing end portion is torn from the remainder of sheet 12along line 34 Where sheet 12 had been precut to facilitate such tearing.Ridding the positive transfer print from the excess processing liquid isthus accomplished by a single, simple; easily performed motion while theexcess processing liquid is retained at all times :between a pair ofsheets so that it does not come into contact with either the apparatusor the fingers of the operator. The processing liquid, by virtue of thefilm-forming agent,

6 functions to adhere trapping sheet 28 to trailing end portion 32, andthis coupled with the fact that the trapping sheet and the trailing endportion are both grasped causes the trapping sheet to strip away fromsheet 12 to which it had originally been adhered thereby leaving asingle sheet containing the positive transfer image and constituting aphotographic-transfer print. The remainder of sheet 12 may then beuncoiled and, if desired, the trailing end portion of sheet 12containing only a negative image on one side may be severed from theremainder of the sheet containing the positive image on the oppositeside; and sheet 12 may be precut for this purpose so that separation ofboth the trapped liquid and the nega tive is performed in one operation.

In another embodiment of the invention, the imagerecording material maybe provided on the side of sheet 12 which faces outwardly whenthe sheetis coiled. In this embodiment, the negative image extends from adjacentthe leading edge of sheet 12 and trapping sheet 28 is located with itsleading edge adjacent the trailing edge of the exposed area. The mass ofliquid is deposited on the opposite side of the sheet from the negativeimage at a location spaced from the leading edge of sheet 12approximately the length of a single convolution. Stated differently,the positions of the negative and positive images are reversed. However,this embodiment is less preferred because it results in waste at bothends of sheet 12 rather than at only one end.

In another embodiment of sheet 12, the photosensitive layer may besupported on a stripping layer in turn supported on sheet 12; and thepositive print may be subjected to an after treatment, e.g., applicationof a solvent for the stripping layer, to remove the image-recordinglayer containing the developed negative image. However, it is felt thatfor document-copying purposes, the presence of a negative image of thedocument on the reverse side of the positive copy of the document shouldnot prove unduly objectionable particularly if material comprising sheet12 is sufliciently opaque so that the negative image is not seen throughthe side of the paper supporting the positive image.

By virtue of the present invention, the production of a positivephotographic print is reduced to a simple, easily performed processrequiring only a minimum of apparatus which need not be expensive orcomplex and utilizes simple and inexpensive materials. The materialsemployed for each copy comprise a single sheet to which is attached asmall sheet and a container of processing liquid. The apparatusincludes, in addition to means for exposing the photosensitive material,means (not shown) for ejecting the fluid contents of the container ontothe sheet, means for rotating roll 18 and means (not shown) forrelieving pressure exerted by member 22 against roll 18, the means notshown being well known to those skilled in the art.

Since certain changes may be made in the above product and processwithout departing from the scope of the invention herein involved, it isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

What is claimed is:

1. In a photographic product including a sheet designed to be treatedwith a liquid by coiling said sheet and distributing said liquid betweenand in contact with successive superposed convolutions of said coiledsheet, in combination:

a layer of a photosensitive image-recording material supported on theside of said sheet;

a retaining sheet approximately equal in width to the first-mentionedsheet and having a length which is substantially less than the length ofsaid first-mentioned sheet;

said retaining sheet being secured to said first-mentioned sheet at theleading edge portion of said retaining sheet with the trailing edge ofsaid retaining sheet spaced from the trailing edge of saidfirstmentioned sheet by-at least the length of a single convolution ofsaid first-mentioned sheet when the latter is coiled such that saidtrailing edge of said first-mentioned sheet extends to said trailingedgev of said retaining sheet when said sheets are coiled; saidretaining sheet being removably secured to said first-mentioned sheet;and

said first-mentioned sheet being precut along a transverse linesubstantially parallel with said trailing edge of said first-mentionedsheet and spaced therefrom by a distance substantially equal to thelength of said retaining sheet in order to promote severance of thetrailing end portion of said first-mentioned sheet from the remainderthereof.

2. The photographic product of claim 1 in which said first-mentionedsheet is provided at its leading end on said one surface with a pressuresensitive adhesive.

3. The photographic product of claim 1 in which said retaining sheet issecured to said first-mentioned sheet by a strippable adhesive.

4. In a photographic product including a sheet designed to be treatedwith a liquid by coiling said sheet and distributing said liquid betweenand in contact with successive superposed convolutions of said coiledsheet, in combination:

a layer of a photosensitive image-recording material supported on oneside of said sheet;

a retaining sheet approximately equal in width to the first-mentionedsheet and having a length which is substantially less than the length ofsaid first-mentioned sheet;

said retaining sheet being secured to the other side of saidfirst-mentioned sheet at the leading edge portion of said retainingsheet with the trailing edge of said retaining sheet spaced from thetrailing edge of said first-mentioned sheet by at least the length of asingle convolution of said first-mentioned sheet when the latter iscoiled such that said trailing edge of said first-mentioned sheetextends to said trailing edge of said retaining sheet when said sheetsare coiled;

said retaining sheet being removably secured to said first-mentionedsheet; and

said first-mentioned sheet being precut along a transverse linesubstantially parallel with said trailing edge of said first-mentionedsheet and spaced therefrom by a distance substantially equal to thelength of said retaining sheet in order to promote severance of thetrailing end portion of said first-mentioned sheet from the remainderthereof.

5. In a photographic product including a sheet designed to be treatedwith a liquid by coiling said sheet and distributing said liquid betweenand in contact with successive superposed convolutions of said coiledsheet, in combination:

a layer of a photosensitive image-recording material on one side of saidsheet;

a retaining sheet approximately equal in width to the first-mentionedsheet and having a length which is substantially less than the length ofsaid first-mentioned sheet;

said retaining sheet being secured to said one side of saidfirst-mentioned sheet at the leading edge portion of said retainingsheet with the trailing edge of said retaining sheet spaced from thetrailing edge of said first-mentioned sheet by at least the length of asingle convolution of said first-mentioned sheet when the latter iscoiled such that said trailing edge of said firstmentioned sheet extendsto said trailing edge of said retaining sheet when said sheets arecoiled;

said retaining sheet being removably secured to said first-mentionedsheet; and

said firsta-mentioned sheet being precut along a transsupported on oneside of said sheet and covering at least an exposure area extendingsubstantially from side to side of said sheet and from a leading edge,spaced from the leading end of said sheet toward the trailing end ofsaid sheet by slightly more than the length of a convolution thereof,'when the latter is coiled, over a major portion thereof;

a generally rectangular trapping sheet at least equal in width to saidexposure area and having a length which is substantially less than thelength of said first-mentioned sheet;

said trapping sheet being secured to one side of said first-mentionedsheet with the leading edge of said trapping sheet spaced from thetrailing edge of said exposure area and the trailing edge of saidtrapping sheet spaced from the trailing edge of said first-mentionedsheet, by said length of a single convolution of said first-mentionedsheet so that said trailing edges of said sheets are aligned when saidfirst-mentioned sheet is completely coiled;

said trapping sheet being secured to said first-mentioned sheet at theleading edge portion of said trapping sheet by a strippable adhesive;

said fi-rst mentioned sheet being precut along a transverse linesubstantially parallel with said trailing edge of said first-mentionedsheet and spaced therefrom by a distance substantially equal to thelength of said trapping sheet in order to promote severance of thetrailing end portion of said first-mentioned sheet from the remainderthereof.

7. A method of producing a positive photographic print comprising:

exposing an area of a layer of photosenstive image-recording materialcarried on one side of a first sheet to produce an image in said layer;

depositing on said one side of said sheet a liquid capable of reactingwith said exposed image-recording material to produce a positivediffusion-transfer image, said liquid being deposited as an elongatedmass extending substantially from side to side of said area across saidsheet and located adjacent the leading edge of said area;

coiling said first sheet upon itself around a supporting member withsaid one side facing inwardly to form a coil having a first innermostconvolution approximately equal in circumference to the distance betweenthe leading and trailing edges of said area.

While coiling said sheet around said supporting member I applyingcompressive pressure progressively to said sheet to distribute saidliquid between and in contact with adjacent surfaces of successiveconvolutions of said sheet toward the trailing end thereof; compressivepressure being applied to said sheet by urg ing a second member towardand into juxtaposition with said supporting member while advancing saidsheet between said members into said coil;

- continuing to advance said second sheet between said members into saidcoil while applying compressive pressure to said first sheet until asecond sheet ad hered to the other side of said first sheet in thevicinity of said trailing end of said first sheet is advanced into saidcoil and becomes engaged between said members for a second time;

whereupon the pressure exerted upon the trailing end portion of saidfirst sheet superposed with said second sheet disposed thereunder isrelieved to collect and retain said liquid between said trailing endportion and said second sheet;

retaining said sheets in a coiled condition during a predeterminedperiod during which said liquid is reacted with said image-recordingmaterial to produce a positive diffusion-transfer reversal image betweenconvolutions of said first sheet on said other side thereof; and

thereafter stripping said second sheet from said first sheet togetherwith said trailing end portion of said first sheet and said liquidretained therebetween, separating said trailing end portion from theremainder of said first sheet carrying said image and uncoiling saidremainder of said first sheet comprising said positive print.

8. The method of claim 7 in which said first sheet is coiled byattaching said first sheet at its leading end to a generally cylindricalsupporting member, urging a second member into juxtaposition with saidsupporting member and rotating said supporting member to coil said sheetthereon and distribute said processing liquid,

9. The method of claim 8 in which said first sheet is attached to saidsupporting member by a pressure sensitive adhesive.

'10. The method of claim 7 in which said mass of liquid is deposited onsaid other side of said first sheet and said first sheet is coiled withsaid one side facing outwardly.

'11. A method of producing a positive photographic print comprising:

photoexposing an area of a layer of photosenstive imagerecordingmaterial carried on one side of a generally rectangular first sheet toproduce an image in said layer, said area and said sheet beingsubstantially rectangular and having leading and trailing edges, saidleading edge of said area being spaced from said leading edge of saidsheet at least a predetermined distance;

depositing on said one side of said sheet a liquid capable of reactingwith said exposed image-recording material to produce a positivediffusion-transfer image, said liquid being deposited on said sheet asan elongated mass extending substantially from side to side of said areaacross said sheet adjacent said leading edge of said area;

coiling said first sheet upon itself around a support member with saidone side facing inwardly to form a coil having a first, innermostconvolution approximately equal in circumference to said predetermineddistance;

while coiling said sheet around said supporting member, applyingcompressive pressure progressively to said sheet to distribute saidliquid between and in contact with adjacent surfaces of successiveconvolutions of said sheet toward said trailing edge thereof;

compressive pressure being applied to said sheet by urging a secondmember toward and into juxtaposition with said supporting member whileadvancing said sheet between said members into said coil;

continuing to advance said second sheet between said members into saidcoil while applying compressive pressure to said first sheet until asecond sheet, having a leading edge adhered to the other side of saidfirst sheet and spaced therefrom by said predetermined distance, isadvanced into said coil and becomes engaged between said members asecond time;

whereupon the pressure exerted upon the trailing end portion of saidfirst sheet superposed with said second sheet is relieved in order tocollect and retain said liquid between said trailing end po'rtion andsaid second sheet;

retaining said sheets in a coiled condition during a predeterminedprocessing period during which said liquid is reacted with saidimage-recording material to produce a positive difEusion-transferreversal image between convolutions of said first sheet on said otherside thereof; and

thereafter stripping said second sheet from said first sheet togetherwith said trailing end portion of said first sheet and said liquidretained therebetween, separating said trailing end portion from theremainder of said first sheet carrying said image and uncoiling saidremainder of said first sheet comprising said positive print.

References Cited by the Examiner UNITED STATES PATENTS 2,088,145 7/1937Von Biehler 96--71 2,686,717 8/1954 Land 96-29 2,740,717 4/ 1956 Yutzyet al 96-29 2,882,151 4/ 1959 Yutzy et al. 96-29 NORMAN G. TORCHI'N,Primary Examiner.

A. E. TANENHOLTZ, J. RAUBITSCHEK,

Assistant Examiners.

1. IN A PHOTOGRAPHIC PRODUCT INCLUDING A SHEET DESIGNED TO BE TREATEDWITH A LIQUID BY COILING SAID SHEET AND DISTRIBUTING SAID LIQUID BETWEENAND IN CONTACT WITH SUCCESSIVE SUPERPOSED CONVOLUTIONS OF SAID COILEDSHEET, IN COMBINATION: A LAYER OF A PHOTOSENSITIVE IMAGE-RECORDINGMATERIAL SUPPORTED ON THE SIDE OF SAID SHEET; A RETAINING SHEETAPPROXIMATELY EQUAL IN WIDTH TO THE FIRST-MENTIONED SHEET AND HAVING ALENGTH WHICH IS SUBSTANTIALLY LESS THAN THE LENGTH OF SAIDFIRST-MENTIONED SHEET; SAID RETAINING SHEET BEING SECURED TO SAIDFIRST-MENTIONED SHEET AT THE LEADING EDGE PORTION OF SAID RETAININGSHEET WITH THE TRAILING EDGE OF SAID RETAINING SHEET SPACED FROM THETRAILING EDGE OF SAID FIRSTMENTIONED SHEET BY AT LEAST THE LENGTH OF ASINGLE CONVOLUTION OF SAID FIRST-MENTIONED SHEET WHEN THE LATTER ISCOILED SUCH THAT SAID TRAILING EDGE OF SAID FIRST-MENTIONED SHEETEXTENDS TO SIAD TRAILING EDGE OF SAID RETAINING SHEET WHEN SAID SHEETSARE COILED; SAID RETAINING SHEET BEING REMOVABLY SECURED TO SAIDFIRST-MENTIONING SHEET; AND SAID FIRST-MENTIONED SHEET BEING PRECUTALONG A TRANSVERSE LINE SUBSTANTIALLY PARALLEL WITH SAID TRAILING EDGEOF SAID FIRST-MENTIONED SHEET AND SPACED THEREFROM BY A DISTANCESUBSTANTIALLY EQUAL TO THE LENGTH OF SAID RETAINING SHEET IN ORDER TOPROMOTE SEVERANCE OF THE TRAILING END PORTION OF SAID FIRST-MENTIONEDSHEET FROM THE REMAINDER THEREOF.
 7. A METHOD OF PRODUCING A POSITIVEPHOTOGRAPHIC PRINT COMPRISING: EXPOSING AN AREA OF A LAYER OFPHOTOSENSTIVE IMAGE-RECORDING MATERIAL CARRIED ON ONE SIDE OF A FIRSTSHEET TO PRODUCE AN IMAGE IN SAID LAYER; DEPOSITING ON SAID ONE SIDE OFSAID SHEET A LIQUID CAPABLE OF REACTING WITH SAID EXPOSEDIMAGE-RECORDING MATERIAL TO PRODUCE A POSITIVE DIFFUSION-TRANSFER IMAGE,SAID LIQUID BEING DEPOSITED AS AN ELONGATED MASS EXTENDING SUBSTANTIALLYFROM SIDE TO SIDE OF SAID AREA ACROSS SAID SHEET AND LOCATED ADJACENTTHE LEADING EDGE OF SAID AREA; COILING SAID FIRST SHEET UPON ITSELFAROUND A SUPPORTING MEMBER WITH SAID ONE SIDE FACING INWARDLY TO FORM ACOIL HAVING A FIRST INNERMOST CONVOLUTION APPROXIMATELY EQUAL INCIRCUMFERENCE TO THE DISTANCE BETWEEN THE LEADING AND TRAILING EDGES OFSAID AREA. WHILE COILING SAID SHEET AROUND SAID SUPPORTING MEMBERAPPLYING COMPRESSIVE PRESSURE PROGRESSIVELY TO SAID SHEET TO DISTRIBUTESAID LIQUID BETWEEN AND IN CONTACT WITH ADJACENT SURFACES OF SUCCESSIVECONVOLUTIONS OF SAID SHEET TOWARD THE TRAILING END THEREOF; COMPRESSIVEPRESSURE BEING APPLIED TO SAID SHEET BY URGING A SECOND MEMBER TOWARDAND INTO JUXTAPOSITION WITH SAID SUPPORTING MEMBER WHILE ADVANCING SAIDSHEET BETWEEN SAID MEMBERS INTO SAID COIL; CONTINUING TO ADVANCE SAIDSECOND SHEET BETWEEN SAID MEMBERS INTO SAID COIL WHILE APPLYINGCOMPRESSIVE PRESSURE TO SAID FIRST SHEET UNTIL A SECOND SHEET ADHERED TOTHE OTHER SIDE OF SAID FIRST SHEET IN THE VICINITY OF SAID TRAILING ENDOF SAID FIRST SHEET IS ADVANCED INTO SAID COIL AND BECOMES ENGAGEDBETWEEN SAID MEMBERS FOR A SECOND TIME; WHEREUPON THE PRESSURE EXERTEDUPON THE TRAILING END PORTION OF SAID FIRST SHEET SUPERPOSED WITH SAIDSECOND SHEET DISPOSED THEREUNDER IS RELIEVED TO COLLECT AND RETAIN SAIDLIQUID BETWEEN SAID TRAILING END PORTION AND SAID SECOND SHEET;RETAINING SAID SHEETS IN A COILED CONDITION DURING A PREDETERMINEDPERIOD DURING WHICH SAID LIQUID IS REACTED WITH SAID IMAGE-RECORDINGMATERIAL TO PRODUCE A POSITIVE DIFFUSION-TRANSFER REVERSAL IMAGE BETWEENCONVOLUTIONS OF SAID FIRST SHEET ON SAID OTHER SIDE THEREOF; ANDTHEREAFTER STRIPPING SAID SECOND SHEET FROM SAID FIRST SHEET TOGETHERWITH SAID TRAILING END PORTION OF SAID FIRST SHEET AND SAID LIQUIDRETAINED THEREBETWEEN, SEPARATING SAID TRAILING END PORTION FROM THEREMAINDER OF SAID FIRST SHEET CARRYING SAID IMAGE AND UNCOILING SAIDREMAINDER OF SAID FIRST SHEET COMPRISING SAID POSITIVE PRINT.